Machines with work implement systems actuated with hydraulic circuits and hydraulic cylinder assemblies may size hydraulic control valves to allow operators more control when work implements are subject to over-running loads. Smaller cross sectional sizing of control valves may also allow fine control of work implement movements during operation. Although smaller cross sectional areas of control valves may allow better control during certain work conditions, they may be less power efficient and slower to respond in comparison to larger cross sectional areas of control valves, when work implements encounter resistive loads.
United States Patent Application Publication US 201010024410 A1, filed by Brickner, discloses a hydraulic system for a machine. The hydraulic system includes an actuator with a first chamber and a second chamber, a first valve, a second valve, a third valve, and an operator input device displaceable from a neutral position to generate a signal indicative of a desired movement of the actuator. The hydraulic system further includes a controller configured to open the first and third valves by amounts related to a signal to pass fluid, and open the second valve by an amount related to the signal to pass fluid when the signal indicates a desire for increased actuator velocity. The third valve may continue to open during opening of the second valve.